Since the late 1980's, laboratory research has indicated the potential of using lasers to “weld” biological tissues together, sometimes facilitated by introducing an albumen solder. Many encouraging results have been obtained, suggesting that lasers hold promise for instant wound closure. An important advantage is achieving an instant, watertight bond. While some laser systems have been developed for use in surgical applications, none has been able to realize a practical system that offers a comparative advantage to standard procedures. This is due primarily to two factors: the systems have attempted to provide general applicability for multiple tissue types, i.e., a one-size-fits-all approach, and the systems require users to exercise a significant amount of experience and skill in detecting changes in tissue appearance while using the laser. In particular, it has been found that different tissues require different sets of laser parameters, e.g., wavelength, pulse duration, power level, exposure time, and pressure. An additional drawback is that, even with optimized performance parameters, use of these test systems is an “art,” requiring an inordinate amount of experience on the part of the operator, despite attempts to automate the feedback and control of the laser devices. Thus, it is easy to burn tissue or end up with an incomplete tissue weld.
During surgical procedures to correct nasal septal deviation—nasal cavity blockage linked to chronic sinusitis and other conditions—bone and cartilage are removed from the centerline of the nose, while preserving the mucoperichodrial flaps covering both sides. These flaps must be brought back together, a procedure called “coaptation.” This prevents blood clotting in-between and hematoma formation. Coaptation must be completed to ensure the survival of septal cartilage. If the flaps are not re-joined, the blood supply will be reduced, killing the remaining cartilage and causing serious, irreversible saddle nose deformity wherein a patient's nose collapses.
Currently coaptation of the tissue membranes lining the septum is accomplished with a needle and suture, stapling, or by intranasal packing. The current suturing method comes with a number of serious shortcomings, including difficulty visualizing and guiding the needle deep in the nasal cavity when working through the nostrils, inadvertent tearing of the vascular nasal wall by the needle (with resultant bleeding leading to immediate visualization problems and to later scarring and healing problems through the development of nasal synechia), and the possibility of breaking or detaching the needle (requiring a radiological scan to ensure removal of all fragments). Stapling can similarly cause bleeding problems with similar side effects. Both suturing and stapling can result in sub-optimal coaptation due to a lack of uniformity in closure. This current suture coaptation method also consumes a relatively long time in the operating room.
The other method currently used, i.e., inserting intranasal packing, is not a benign procedure. In addition to causing discomfort for patients (the material is left in the nose for 24 to 72 hours), studies show that the intranasal packing reduces oxygen saturation and can lead to toxic shock syndrome. In addition to packing, flat splints are often placed in the nostrils on each side of the septal wall to prevent fibrous growth that could potentially cause nasal synechia as a result of a needle tearing and pushing or pulling mucosa cells into the nasal cavity during suturing.
Repairing and grafting nerves and blood vessels using a microscope present many difficulties for traditional surgical closure techniques, e.g., sutures, staples, and clips. The small size of the tissues involved necessitate specialized thread and needles. For conventional procedures, suture with a diameter on the order of 0.1 mm is common. Microsurgical procedures can require suture two orders of magnitude smaller, down to 0.001 mm. Surgeons must train extensively to compensate for hand tremor, which is significant given the small structures to be joined.
The information included in this Background section of the specification, including any references cited herein and any description or discussion thereof, is included for technical reference purposes only and is not to be regarded subject matter by which the scope of the invention is to be bound.